Summon Demon Engines

Spellswallow X (As part of this spells casting cost,
you may exile any number of instants and sorceries
from your graveyard and/or hand.)
You may search your library for any number of
Demon Constructs with converted mana cost X
or less and put them onto the battlefield tapped,
where X is the number of cards exiled with
this spells Spellswallow ability.